Differences in grapevine rootstocks sensitivity and recovery from drought are linked to fine root cortical lacunae and root tip function

Authors: CUNEO, ITALO - Pontifical Catholic University Of Valparaiso; BARRIOS-MASIAS, FELIPE - University Of Nevada; KNIPFER, THORSTEN - University Of California, Davis; URETSKY, JAKE - University Of California, Davis; REYES, CLARISSA - University Of California, Davis; LENAIN, PIERRE - University Of California, Davis; BRODERSEN, CRAIG - Yale University; WALKER, M.ANDY - University Of California, Davis; McElrone, Andrew

Submitted to: New Phytologist
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/15/2020
Publication Date: 12/7/2020
Citation: Cuneo, I., Barrios-Masias, F., Knipfer, T., Uretsky, J., Reyes, C., Lenain, P., Brodersen, C., Walker, M., Mcelrone, A.J. 2020. Differences in grapevine rootstocks sensitivity and recovery from drought are linked to fine root cortical lacunae and root tip function. New Phytologist. 229(1):272-283. https://doi.org/10.1111/nph.16542.
DOI: https://doi.org/10.1111/nph.16542

Interpretive Summary:

Technical Abstract: Some grapevine rootstocks perform better than others during and after drought events, yet little is known about links between the anatomical and physiological characteristics underlying these differential responses. Here, we compared root system structure and function of fine roots in two grapevine rootstocks (110R and 101-14Mgt). We found that rapid re-establishment of root elongation, water uptake capacity (i.e. partial recovery of Lpr) and water depletion surrounding the root tips as imaged by with neutron radiography (NR), after re-watering were observed in 110R, but not in 101-14Mgt. Lacunae formation in drought-stressed fine root cortical cells (~5cm back from the root tip) was associated with a significant decrease in fine root hydraulic conductivity (Lpr) for both rootstocks, however, the onset of lacuna formation occurred more rapidly and under milder stress for the drought resistant rootstock, 110R. Suberin was deposited more consistently and at an earlier developmental stage in fine roots of 101-14Mgt, which might limit cortical lacunae formation during mild drought stress but also limit water absorption upon re-watering. Based on our results, we postulate that drought resistance in grapevine rootstocks is associated with rapid re-establishment of growth and water uptake capacity in the root tip upon re-watering by limiting competing sites along the root cylinder.